Frustrated Frequent Fliers Wait as Kinks Get Ironed Out

The wedding of Southwest and AirTran airlines is now in its third year. For many of the carriers' regular passengers, the honeymoon ended long ago.

As the two airlines, which combined carry more domestic passengers than any other, have started splicing together their flight schedules this year, travelers say Southwest Airlines agents struggle with AirTran Airways tickets and vice versa, sometimes leaving passengers who have been...